Review on Dell P2721Q Ultra Thin DisplayPort Certified 4K 3840x2160P Monitor with 🖥️ Flicker-Free Technology and Multi-Adjustment Stand, USB-C Connectivity - Dell 27 4K Monitor by Adam Bass

I bought this monitor for home office use with the new M1 MacBook Pro. Unfortunately, the display did not recognize the USB-C signal from my laptop even after several cable attempts. Also, the various USB ports on the monitor didn't power my phone or tablet as advertised. I was also surprised by the slight lag and choppy movement of the mouse pointer on the screen compared to the native display. My much older 24" Dell monitor that I'm replacing was smoother. The picture itself is good. I was able to connect via HDMI using an adapter. It works, but not quite the streamlined setup I was hoping for. UPDATE: I managed to resolve some of the issues described above. The lag was due to the monitor running at a 30Hz refresh rate instead of 60Hz. For some reason Mac OS Big Sur defaults to 30Hz. You have to access hidden options to change the refresh rate. In the display settings, hold the option key while pressing "scaled" and check the "display low resolution mode" box. This will open options for additional resolutions and a refresh rate menu at the bottom of the dialog box. Increasing to 60Hz made the monitor very smooth with no lag. If you're using an HDMI connection, you'll need to make sure your cable (and USB-C adapter, if used) supports 60Hz at 4K. It's frustrating that macOS defaults to subpar settings and makes changing them so cryptic, especially for such a powerful system. I still couldn't connect video via USB-C so I have to use 2 connections. But the USB-C hub function works now. Now my laptop has two cables attached instead of one, which is still less optimized than I was hoping. However, I think this is a Mac issue, not a Dell issue, and I hope it gets fixed in a future macOS update.